Glowing stars?

I can’t find this topic, though I feel like I’m asking the obvious: Why are two of my stars glowing?
They look identical to the rest, except for a fuzzy halo behind the star in my player colour. there’s nothing I’ve noticed to set them apart… production, fleets, or enemy action…

Those stars have Warp Gates. If you look at the star info in the UI, you will see you have the option to destroy them. If you look at a star without them, there will be an option to buy one in the same place in the UI.

You must be playing a game that randomly gives free warpgates at startup, it is one of the game options.

In case you are unaware what they are, they permit much faster travel between two warpgates in range. Here is the help page: Neptune's Pride

Thank you Solrax, that’s excatly it.
I knew it would be obvious when someone pointed it out!